|Publication number||US6510995 B2|
|Application number||US 09/810,142|
|Publication date||28 Jan 2003|
|Filing date||16 Mar 2001|
|Priority date||16 Mar 2001|
|Also published as||CN1459216A, CN100367827C, DE60221654D1, DE60221654T2, EP1374642A1, EP1374642B1, US20020145041, WO2002076150A1|
|Publication number||09810142, 810142, US 6510995 B2, US 6510995B2, US-B2-6510995, US6510995 B2, US6510995B2|
|Inventors||Subramanian Muthu, Chin Chang|
|Original Assignee||Koninklijke Philips Electronics N.V.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (139), Classifications (10), Legal Events (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to commercial display systems and the like, and more particularly, to an improved method and apparatus for lighting such commercial display systems and the like. The invention has particular applications in commercial refrigeration systems used in a retail environment, such as retail display freezers.
Red-Green-Blue (RGB) based white Light Emitting Diode (“LED”) illumination is known in the art and is finding applications in backlighting for LCD panels, lighting for commercial freezers, signage etc. For these applications, linear power supplies or switch-mode power supplies are used to drive the LEDs. The efficiency of the overall system with the use of linear power supply is low and the switch-mode power supply overcomes this problem. Since there are three LED light sources, three independent power supplies are used to drive the LEDs with a proper current control scheme. In this configuration, each power supply may contain independent AC/DC converter, a power factor correction unit, an isolation transformer, and a DC/AC converter system. There exists a redundancy in this scheme due to the three independent AC/DC converters, power factor correction unit, and the isolation transformer. In addition, it requires independent control of the converters in the power supplies. This scheme results in increase in cost, complexity in control and poor performance.
A still further problem with the present state of the art is accurately controlling the amount of each type of light emitted. More specifically, the color of the light resulting from the combination of the light emitted by the red, green, and blue lights is determined largely by the relative amounts of each type of light that gets mixed together. The light source associated with each type of light has a different sensitivity to age and temperature, as well as other factors. As a result, maintaining the appropriate amount of each color of light such that the resultant total light amount is correct is a difficult if not impossible task.
Another issue not addressed by prior systems is the fact that in a display case or retail display refrigeration device, the type and amount of light used to display particular products may influence a consumer's purchasing decisions. There exists no technique of uniformly assuring that each specific product is displayed using the optimum lighting conditions.
The above and other problem of the prior art are overcome in accordance with the present invention which relates to an LED current driver for a lighting system applicable in commercial displays. In accordance with the invention, drivers are utilized to drive red, green, and blue LEDs in a specified proportion with one another. A feedback loop transmits color and intensity information to a microprocessor, which adjusts the values of each of the red, green, and blue lights to achieve a prescribed lighting intensity and color.
In an enhanced embodiment, a computer and storage are provided for determining the intensity and color of light used based upon specific products being displayed, or specific times of day. Specifically, a computer may adjust the light color and/or intensity to optimize display at particular times or for particular products. In one exemplary embodiment, a microprocessor controlled AC distributed power supply system is used to provide LED drive currents to a white LED luminary for lighting commercial freezers. The AC distributed system contains a front-end AC/DC converter with power factor correction, a high frequency inverter, an isolation transformer and three DC/AC converters with RGB drive current control system. A single, front-end AC/DC converter system converts the AC supply and maintains a constant DC link voltage as the input to the high frequency DC/AC inverter. The AC/DC converter also performs the power factor correction at the AC mains. The high frequency converter converts the DC voltage to AC and supplies powers to three AC/DC converters with LED drive current control.
The power converter system is controlled by a microprocessor system. The microprocessor system provides an integrated closed loop control and the PWM generation for the converter systems, in addition to the control of the white light generated by the LED luminary. This approach provides an integral solution for the control of the LED driver system. The control algorithm for the microprocessor system is developed for modularity and with multi-processing features, to provide the effective controlling capabilities for the microprocessor system.
The microprocessor system is also optionally connected to a user computer, which is programmed with the food that will be displayed in the freezers. The computer in the shop selects the suitable white color point and the lighting level that should be generated by the system when a specified food is being displayed in the freezers, based upon programmed user priorities. The computer supplies this information to the microprocessor system at the appropriate times, which controls the driver system to produce the required color and lighting level. Therefore, the selection of the color and lighting level for the displayed food is automated. The computer can also start and stop the freezer driver such that the freezer lights are switched off automatically when it is not needed, and therefore, the power saving is achieved.
In another enhanced embodiment, the system is arranged to accept data from an input device, such as a hand held keyboard or bar code scanner.
FIG. 1 represents a block diagram overview of the exemplary embodiment of the present invention;
FIG. 2 depicts a representation of a distributed power supply for use in connection with the present invention;
FIG. 3 shows a second embodiment of a distributed power system for use in driving the lights in accordance with an exemplary embodiment of the present invention; and
FIG. 4 shows the user interface for selecting a particular color for the lighting system.
FIG. 1 presents the overview of the microprocessor controlled AC power supply system for RGB LED based freezer driver in accordance with an exemplary embodiment of the invention. The power is supplied by front-end AC/DC converter 10, high frequency DC/AC converter 20, and three load-end AC/DC converters 30, 31 and 32 for providing RGB LED drive currents. The system includes Red, Green and Blue LED light sources 120, 130 and 140 respectively. Each Red, Green and Blue LED light source is made of a plurality of LEDs connected in a suitable series and/or parallel configuration.
The light source also houses light sensors such as photo-diodes and heat-sink temperature sensors (not shown) for closed-loop feedback control of the white light. The light output of the light source may be supplied to mixing optics and an optical fiber system (not shown) for transmission of the light into the freezer or similar environment. However, any suitable means of conveying the light is acceptable.
The system is controlled by a Microprocessor system 50. The Microprocessor system uses feedback system 62 to convey variables to the Microprocessor 50. Control signals are provided to PWM generation and isolation 61 as shown for use in controlling DC/AC converter 20. By adjusting the amplitude and/or duty cycle of the PWM signal produced, the power to each driver 30-32 is adjusted.
The microprocessor system is connected to a user interface and a messaging display system 64. The microprocessor system is also interfaced to an optional computer 51, or to the computer network 53 either via infrared communications or though series/parallel ports 52.
The primary function of the front-end AC/DC converter 10 is to convert the AC supply voltage to a DC voltage. In addition, the AC/DC converter 10 is made to perform the power factor correction at the AC mains, possibly with universal voltage range input. The front-end AC/DC converter 10 can be based on Flyback or Boost topologies.
The feedback control system for the output voltage and the power factor correction at the AC mains is carried out by the microprocessor 50 which outputs the necessary control signals via the PWM generation and the isolation block 61. The PWM gating signals are also generated by the microprocessor 50. For this, the line current is also one of the feedback variables in addition to the DC link voltage. This is shown at 62.
The microprocessor 50 then directly provides the PWM gating signals to the AC/DC converter 10. Alternatively, the power factor correction and the PWM function can be carried out externally. In this case, the AC/DC converter contains the necessary function blocks for the PFC and the PWM generation.
The output of the AC/DC converter system is connected to the input section of the high frequency DC/AC inverter system 20. The DC/AC converter system converts the DC voltage to a high frequency AC voltage. The DC/AC converter is realized either by resonant converter or a square wave converter topology. As an example, the DC/AC converter system based on a resonant converter topology is shown in FIG. 2. In FIG. 2, the resonant converter system is based on the half bridge converter system 202 connected to a resonant tank 201. Alternatively, a full bridge configuration can also be used. The output of the converter is fed to a suitable resonant tank, whose output is connected to a high frequency isolation transformer 203. The transformers then drive converters 30-32 as shown.
Certain simplifications are possible for particular applications. For example, when the light output level is not high, some single stage circuits could be utilized. FIG. 3 shows an additional embodiment of the power supply system of FIG. 2. The arrangement of FIG. 3 includes three Flyback converters operated with unity power factor correction, connected in parallel. In this case, the AC distributed system is realized at the line frequency of the input voltage. Such system is also controlled by microprocessor 50.
Returning to FIG. 1, the outputs of the AC/DC converters 30-32 are connected to the RGB LED light sources, and provide regulated drive currents to the LED light sources 120, 130 and 140. The RGB LED light sources may be supplied either with the constant DC current or by PWM current pulse. The magnitude of the DC current or the duty ratio of the PWM current pulses is determined by a white light control system in order to control the color and the lighting level of the white light in accordance with known techniques. The control system is also executed by the microprocessor.
A suitable light sensor 40 and a heat sink temperature sensor 41, as shown in FIG. 1, are used to sense the light output and the heat sink temperature of the LEDs. These parameters are fed into the microprocessor 50, through feedback circuit 62. The microprocessor 50 calculates the color and the lighting level of the white luminary. Then, the microprocessor 50 obtains the required LED drive currents or the PWM gating pulse widths. The AC/DC converter is then controlled to provide the required LED drive currents.
For inputting the feedback signals into the microprocessor system, the feed back circuit 62, is used. The feed back circuit 62 includes sensing and conditioning circuits for inputting the feed back signals directly to the analog-to-digital converter 161 in the microprocessor system 50. The feed back variables may comprise the LED light source output from LEDs 120, 130 and 140, heat sink temperature from sensor 41, LED drive currents, DC link voltages, and/or line currents.
The feed back circuit also contains fault-sensing circuits, which generate interrupts upon a fault. The outputs of the fault sensing circuits are directly connected to non-maskable interrupts in the microprocessor system.
The microprocessor 50 directly provides the PWM gating signals, which are first passed through an isolation circuit 61. The outputs of this isolation circuit are fed into individual MOSFET drivers in AC/DC converter 10, DC/AC converter 20, and LED drivers 30,31, and 32.
The microprocessor 50 is also connected to a user interface system 63, for manually selecting the color and the lighting level for the white light. An exemplary embodiment of the user interface system 63 is shown in FIG. 4, which comprises switches 401-403 and switch decoding logic 404. When a switch is closed, the decoding logic 404 detects the switch closure and outputs the data in digital form. The output of the decoding logic can be interfaced to the microprocessor 50 using either infrared communications or via cables or other means. The user interface 64 also contains on ON/OFF switch 401 for starting and stopping the system, and switches 402 and 403 for selecting color and light level.
The microprocessor 50 is also connected to a message display system 64, which is used to display the status of the microprocessor system such as the selected color, system condition, and the lighting levels.
The microprocessor 50 may include at least one CPU or a DSP 160, analog interface devices 161 such as analog-to-digital converter and digital-to-analog converter system, digital interfaces 162 such as serial input/output, infrared port, JTAG interface, digital ports, and other devices 163 such as memory, timers and a clock. A multi-processor system with more than one microprocessor can be used if all the control functions and the PWM generation are implemented in the microprocessor system.
The output of the feed back circuit 62 for sensing light, LED drive currents, and the DC link voltage are input to the analog-to-digital converters 161, which converts the analog signals to digital for the use by the control algorithms.
The microprocessor system is also connected to a computer 51, which contains the information about the food, and the time and the date of the food that will be displayed in the freezer. The computer is also programmed to select a proper white color point and the lighting level based on the food that will be displayed. The microprocessor system can be interfaced to this computer either via an infrared port, or through a serial port or parallel port or a JTAG connector. The microprocessor system is properly equipped with a suitable interfacing system to handle such connectivity. The computer then supplies the information for the color and the lighting level of the white light depending on the food that is being displayed. Therefore, the selection of the color and dimming level for the white light is automated and the appropriate white light is automatically generated based on the food.
The computer also contains the information about the operational hours for the shop. Therefore, it can start the LED freezer light source when the shop is opened and shut down the driver when the shop is closed. This arrangement results in automatic power savings.
Alternatively, rather than use time, the computer may either locally store or access a database of all products. When the user puts product into a freezer, he/she scans it into the computer using an optional bar code reader, hand held keyboard, or other similar device. The computer then sets the light levels and colors in accordance with the stored information for that product by performing a table look up.
While the above describes the preferred embodiment of the invention, various other modifications and additions will be apparent to those of skill in the art. These modifications are intended to fall within the scope of the following claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4859832 *||2 Sep 1987||22 Aug 1989||Nikon Corporation||Light radiation apparatus|
|US5508825 *||6 Dec 1993||16 Apr 1996||Canon Kabushiki Kaisha||Image processing system having automatic focusing device|
|US5808286 *||3 Jun 1996||15 Sep 1998||Asahi Kogaku Kogyo Kabushiki Kaisha||Data symbol reader utilizing ambient light illumination|
|US6084692 *||16 Oct 1997||4 Jul 2000||Canon Kabushiki Kaisha||Image forming apparatus|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US6630801 *||22 Oct 2001||7 Oct 2003||Lümileds USA||Method and apparatus for sensing the color point of an RGB LED white luminary using photodiodes|
|US6753661 *||17 Jun 2002||22 Jun 2004||Koninklijke Philips Electronics N.V.||LED-based white-light backlighting for electronic displays|
|US6978936 *||23 Apr 2002||27 Dec 2005||Metpologic Instruments, Inc.||Method of and system for automatically producing digital images of moving objects, with pixels having a substantially uniform white level independent of the velocities of the moving objects|
|US6992803 *||8 May 2001||31 Jan 2006||Koninklijke Philips Electronics N.V.||RGB primary color point identification system and method|
|US7088059||21 Jul 2004||8 Aug 2006||Boca Flasher||Modulated control circuit and method for current-limited dimming and color mixing of display and illumination systems|
|US7119496 *||5 Jun 2002||10 Oct 2006||Koninklijke Philips Electronics, N.V.||Inverter for liquid crystal display, and power supply arrangement comprising such an inverter|
|US7176640 *||16 Aug 2005||13 Feb 2007||Sony Corporation||Device for controlling light emission rates of a backlight|
|US7233115||14 Mar 2005||19 Jun 2007||Color Kinetics Incorporated||LED-based lighting network power control methods and apparatus|
|US7256554 *||14 Mar 2005||14 Aug 2007||Color Kinetics Incorporated||LED power control methods and apparatus|
|US7324076 *||28 Jul 2004||29 Jan 2008||Avago Technologies Ecbu Ip (Singapore) Pte. Ltd.||Methods and apparatus for setting the color point of an LED light source|
|US7358706||14 Mar 2005||15 Apr 2008||Philips Solid-State Lighting Solutions, Inc.||Power factor correction control methods and apparatus|
|US7391162 *||12 Apr 2005||24 Jun 2008||Aqua Signal Aktiengesellschaft||Luminaire with LED(s) and method for operating the luminaire|
|US7432463 *||3 Sep 2003||7 Oct 2008||Vantage Controls, Inc.||Button assembly with status indicator and programmable backlighting|
|US7459864||14 Mar 2005||2 Dec 2008||Philips Solid-State Lighting Solutions, Inc.||Power control methods and apparatus|
|US7499016 *||19 May 2005||3 Mar 2009||Samsung Mobile Display Co., Ltd.||Liquid crystal display device|
|US7505268||5 Apr 2006||17 Mar 2009||Tir Technology Lp||Electronic device package with an integrated evaporator|
|US7511437||8 May 2006||31 Mar 2009||Philips Solid-State Lighting Solutions, Inc.||Methods and apparatus for high power factor controlled power delivery using a single switching stage per load|
|US7542257||12 Sep 2005||2 Jun 2009||Philips Solid-State Lighting Solutions, Inc.||Power control methods and apparatus for variable loads|
|US7557521 *||14 Mar 2005||7 Jul 2009||Philips Solid-State Lighting Solutions, Inc.||LED power control methods and apparatus|
|US7573729 *||5 Nov 2004||11 Aug 2009||Koninklijke Philips Electronics N.V.||Resonant power LED control circuit with brightness and color control|
|US7598683||31 Jul 2007||6 Oct 2009||Lsi Industries, Inc.||Control of light intensity using pulses of a fixed duration and frequency|
|US7631986||31 Oct 2007||15 Dec 2009||Koninklijke Philips Electronics, N.V.||Lighting device package|
|US7635957 *||1 Sep 2004||22 Dec 2009||Koninklijke Philips Electronics, N.V.||LED temperature-dependent power supply system and method|
|US7659673||14 Mar 2005||9 Feb 2010||Philips Solid-State Lighting Solutions, Inc.||Methods and apparatus for providing a controllably variable power to a load|
|US7701151||19 Oct 2007||20 Apr 2010||American Sterilizer Company||Lighting control system having temperature compensation and trim circuits|
|US7712917||21 May 2007||11 May 2010||Cree, Inc.||Solid state lighting panels with limited color gamut and methods of limiting color gamut in solid state lighting panels|
|US7737643||20 Jul 2007||15 Jun 2010||Philips Solid-State Lighting Solutions, Inc.||LED power control methods and apparatus|
|US7755506||3 Sep 2004||13 Jul 2010||Legrand Home Systems, Inc.||Automation and theater control system|
|US7778262||6 Sep 2006||17 Aug 2010||Vantage Controls, Inc.||Radio frequency multiple protocol bridge|
|US7781990 *||10 Jun 2008||24 Aug 2010||Industrial Technology Research Institute||Illumination brightness and color control system and method therefor|
|US7812551||25 Mar 2009||12 Oct 2010||American Sterilizer Company||Lighting control method having a light output ramping function|
|US7834885 *||9 May 2007||16 Nov 2010||Samsung Electronics Co., Ltd.||Display apparatus and image processing method thereof|
|US7872430||17 Nov 2006||18 Jan 2011||Cree, Inc.||Solid state lighting panels with variable voltage boost current sources|
|US7906794||4 Jul 2007||15 Mar 2011||Koninklijke Philips Electronics N.V.||Light emitting device package with frame and optically transmissive element|
|US7926300||6 Mar 2006||19 Apr 2011||Cree, Inc.||Adaptive adjustment of light output of solid state lighting panels|
|US7950817||17 Jul 2008||31 May 2011||Abl Ip Holding Llc||Lighting assemblies for vending machines|
|US7959320||22 Jan 2007||14 Jun 2011||Philips Solid-State Lighting Solutions, Inc.||Methods and apparatus for generating and modulating white light illumination conditions|
|US7959325||17 Nov 2006||14 Jun 2011||Cree, Inc.||Solid state lighting units and methods of forming solid state lighting units|
|US7969097||30 May 2007||28 Jun 2011||Cree, Inc.||Lighting device with color control, and method of lighting|
|US7990078||3 Mar 2010||2 Aug 2011||American Sterilizer Company||Lighting control system having a trim circuit|
|US7993021||17 Nov 2006||9 Aug 2011||Cree, Inc.||Multiple color lighting element cluster tiles for solid state lighting panels|
|US8008676||24 May 2007||30 Aug 2011||Cree, Inc.||Solid state light emitting device and method of making same|
|US8016470||8 Oct 2008||13 Sep 2011||Dental Equipment, Llc||LED-based dental exam lamp with variable chromaticity|
|US8049709||8 May 2007||1 Nov 2011||Cree, Inc.||Systems and methods for controlling a solid state lighting panel|
|US8070325||23 Jun 2010||6 Dec 2011||Integrated Illumination Systems||LED light fixture|
|US8120277||4 Jun 2008||21 Feb 2012||Boca Flasher, Inc.||Hybrid-control current driver for dimming and color mixing in display and illumination systems|
|US8123375||17 Nov 2006||28 Feb 2012||Cree, Inc.||Tile for solid state lighting|
|US8144144||2 May 2008||27 Mar 2012||Semiconductor Energy Laboratory Co., Ltd.||Display device|
|US8148236||25 Nov 2008||3 Apr 2012||Semiconductor Energy Laboratory Co., Ltd.||Display device and method for manufacturing thereof|
|US8148854||20 Mar 2009||3 Apr 2012||Cooper Technologies Company||Managing SSL fixtures over PLC networks|
|US8159148 *||16 Jan 2007||17 Apr 2012||Chimei Innolux Corporation||Light emitting diode light source module|
|US8159150 *||23 Apr 2007||17 Apr 2012||Koninklijke Philips Electronics N.V.||Method and apparatus for light intensity control|
|US8165786||23 Jul 2010||24 Apr 2012||Honeywell International Inc.||System for particulate matter sensor signal processing|
|US8174205||8 May 2008||8 May 2012||Cree, Inc.||Lighting devices and methods for lighting|
|US8203286||23 Dec 2010||19 Jun 2012||Cree, Inc.||Solid state lighting panels with variable voltage boost current sources|
|US8243278||15 May 2009||14 Aug 2012||Integrated Illumination Systems, Inc.||Non-contact selection and control of lighting devices|
|US8247989 *||6 Oct 2008||21 Aug 2012||Au Optronics Corp.||Lamp detection driving system and related detection driving method|
|US8255487||12 Sep 2008||28 Aug 2012||Integrated Illumination Systems, Inc.||Systems and methods for communicating in a lighting network|
|US8264172||30 Jan 2009||11 Sep 2012||Integrated Illumination Systems, Inc.||Cooperative communications with multiple master/slaves in a LED lighting network|
|US8277048||14 Jan 2010||2 Oct 2012||Alcon Research, Ltd.||Ophthalmic endoillumination using fiber generated light|
|US8278845||26 Sep 2011||2 Oct 2012||Hunter Industries, Inc.||Systems and methods for providing power and data to lighting devices|
|US8278846||17 Nov 2006||2 Oct 2012||Cree, Inc.||Systems and methods for calibrating solid state lighting panels|
|US8283904||13 Sep 2007||9 Oct 2012||Cree, Inc.||Circuitry for supplying electrical power to loads|
|US8330393||21 Apr 2008||11 Dec 2012||Analog Devices, Inc.||System for time-sequential LED-string excitation|
|US8330710||11 Oct 2011||11 Dec 2012||Cree, Inc.||Systems and methods for controlling a solid state lighting panel|
|US8350491 *||9 Jun 2008||8 Jan 2013||The Sloan Company, Inc.||Self adjusting power supply apparatus and method|
|US8384294||5 Oct 2010||26 Feb 2013||Electronic Theatre Controls, Inc.||System and method for color creation and matching|
|US8421368||15 May 2009||16 Apr 2013||Lsi Industries, Inc.||Control of light intensity using pulses of a fixed duration and frequency|
|US8436553||4 Aug 2011||7 May 2013||Integrated Illumination Systems, Inc.||Tri-light|
|US8441206||29 Mar 2012||14 May 2013||Cree, Inc.||Lighting devices and methods for lighting|
|US8449130||25 Mar 2010||28 May 2013||Cree, Inc.||Solid state lighting panels with limited color gamut and methods of limiting color gamut in solid state lighting panels|
|US8456388||14 Feb 2007||4 Jun 2013||Cree, Inc.||Systems and methods for split processor control in a solid state lighting panel|
|US8461776 *||11 May 2012||11 Jun 2013||Cree, Inc.||Solid state lighting panels with variable voltage boost current sources|
|US8466585||17 Feb 2012||18 Jun 2013||Cooper Technologies Company||Managing SSL fixtures over PLC networks|
|US8469542||16 Jan 2008||25 Jun 2013||L. Zampini II Thomas||Collimating and controlling light produced by light emitting diodes|
|US8488930||9 Dec 2010||16 Jul 2013||Alcon Research, Ltd.||Wavelength converting illumination probe|
|US8514210||21 May 2007||20 Aug 2013||Cree, Inc.||Systems and methods for calibrating solid state lighting panels using combined light output measurements|
|US8556464||31 May 2011||15 Oct 2013||Cree, Inc.||Solid state lighting units and methods of forming solid state lighting units|
|US8567982||9 Dec 2011||29 Oct 2013||Integrated Illumination Systems, Inc.||Systems and methods of using a lighting system to enhance brand recognition|
|US8585245||23 Apr 2010||19 Nov 2013||Integrated Illumination Systems, Inc.||Systems and methods for sealing a lighting fixture|
|US8593074||12 Jan 2011||26 Nov 2013||Electronic Theater Controls, Inc.||Systems and methods for controlling an output of a light fixture|
|US8604709||13 May 2010||10 Dec 2013||Lsi Industries, Inc.||Methods and systems for controlling electrical power to DC loads|
|US8633649||14 Feb 2013||21 Jan 2014||Electronic Theatre Controls, Inc.||System and method for color creation and matching|
|US8674368||28 Mar 2012||18 Mar 2014||Semiconductor Energy Laboratory Co., Ltd.||Display device and method for manufacturing thereof|
|US8678616||5 Apr 2011||25 Mar 2014||Abl Ip Holding Llc||LED luminaire for display cases|
|US8710770||12 Sep 2011||29 Apr 2014||Hunter Industries, Inc.||Systems and methods for providing power and data to lighting devices|
|US8723450||12 Jan 2011||13 May 2014||Electronics Theatre Controls, Inc.||System and method for controlling the spectral content of an output of a light fixture|
|US8742686||24 Sep 2008||3 Jun 2014||Integrated Illumination Systems, Inc.||Systems and methods for providing an OEM level networked lighting system|
|US8810141 *||14 Sep 2012||19 Aug 2014||Mitsubishi Chemical Corporation||Illumination light control apparatus and LED illumination system|
|US8823630||18 Dec 2007||2 Sep 2014||Cree, Inc.||Systems and methods for providing color management control in a lighting panel|
|US8829820||10 Aug 2007||9 Sep 2014||Cree, Inc.||Systems and methods for protecting display components from adverse operating conditions|
|US8866410||24 Oct 2008||21 Oct 2014||Cree, Inc.||Solid state lighting devices and methods of manufacturing the same|
|US8894437||19 Jul 2012||25 Nov 2014||Integrated Illumination Systems, Inc.||Systems and methods for connector enabling vertical removal|
|US8903577||30 Oct 2009||2 Dec 2014||Lsi Industries, Inc.||Traction system for electrically powered vehicles|
|US8936377||31 Mar 2010||20 Jan 2015||Alcon Research, Ltd.||Apparatus for enhancing brightness of a wavelength converting element|
|US8941331||17 May 2013||27 Jan 2015||Cree, Inc.||Solid state lighting panels with variable voltage boost current sources|
|US8981677||8 Apr 2013||17 Mar 2015||Cree, Inc.||Lighting devices and methods for lighting|
|US8999467||18 Aug 2006||7 Apr 2015||Koninklijke Philips N.V.||Cured coating for use in optics or electronics|
|US9024541||7 Mar 2014||5 May 2015||Cirrus Logic, Inc.||Utilizing secondary-side conduction time parameters of a switching power converter to provide energy to a load|
|US9025347||16 Dec 2011||5 May 2015||Cirrus Logic, Inc.||Switching parameter based discontinuous mode-critical conduction mode transition|
|US9066381||16 Mar 2012||23 Jun 2015||Integrated Illumination Systems, Inc.||System and method for low level dimming|
|US9084308 *||6 May 2013||14 Jul 2015||Starfield Controls, Inc.||Self calibrating, adaptive setpoint daylighting|
|US9084316||4 Nov 2011||14 Jul 2015||Cirrus Logic, Inc.||Controlled power dissipation in a switch path in a lighting system|
|US20030011832 *||8 May 2001||16 Jan 2003||Chin Chang||RGB primary color point identification system and method|
|US20040052076 *||19 Dec 2002||18 Mar 2004||Mueller George G.||Controlled lighting methods and apparatus|
|US20040090191 *||4 Nov 2003||13 May 2004||Color Kinetics, Incorporated||Multicolored led lighting method and apparatus|
|US20040105261 *||11 Nov 2003||3 Jun 2004||Color Kinetics, Incorporated||Methods and apparatus for generating and modulating illumination conditions|
|US20040160791 *||5 Jun 2002||19 Aug 2004||Haus Thomas A.J.||Inverter for liquid crystal display, and power supply arrangement comprising such an inverter|
|US20040163936 *||3 Sep 2003||26 Aug 2004||Clegg Paul T.||Button assembly with status indicator and programmable backlighting|
|US20050030744 *||31 Aug 2004||10 Feb 2005||Color Kinetics, Incorporated||Methods and apparatus for generating and modulating illumination conditions|
|US20050040774 *||4 Oct 2004||24 Feb 2005||Color Kinetics, Inc.||Methods and apparatus for generating and modulating white light illumination conditions|
|US20050151489 *||16 Nov 2004||14 Jul 2005||Color Kinetics Incorporated||Marketplace illumination methods and apparatus|
|US20050213352 *||14 Mar 2005||29 Sep 2005||Color Kinetics Incorporated||Power control methods and apparatus|
|US20050213353 *||14 Mar 2005||29 Sep 2005||Color Kinetics Incorporated||LED power control methods and apparatus|
|US20050218838 *||14 Mar 2005||6 Oct 2005||Color Kinetics Incorporated||LED-based lighting network power control methods and apparatus|
|US20050218870 *||14 Mar 2005||6 Oct 2005||Color Kinetics Incorporated||Power control methods and apparatus|
|US20050219872 *||14 Mar 2005||6 Oct 2005||Color Kinetics Incorporated||Power factor correction control methods and apparatus|
|US20050231133 *||14 Mar 2005||20 Oct 2005||Color Kinetics Incorporated||LED power control methods and apparatus|
|US20060007099 *||19 May 2005||12 Jan 2006||Eun-Jung Oh||Liquid crystal display device|
|US20060012987 *||11 Nov 2003||19 Jan 2006||Color Kinetics, Incorporated||Methods and apparatus for generating and modulating illumination conditions|
|US20060016960 *||22 Feb 2005||26 Jan 2006||Color Kinetics, Incorporated||Systems and methods for calibrating light output by light-emitting diodes|
|US20060017402 *||21 Jul 2004||26 Jan 2006||Mckinney Steven J||Modulated control circuit and method for current-limited dimming and color mixing of display and illumination systems|
|US20060022999 *||28 Jul 2004||2 Feb 2006||Lee Joon C||Methods and apparatus for setting the color point of an LED light source|
|US20060038511 *||16 Aug 2005||23 Feb 2006||Sony Corporation||Control device|
|US20060109649 *||30 Dec 2005||25 May 2006||Color Kinetics Incorporated||Methods and apparatus for controlling a color temperature of lighting conditions|
|US20060152172 *||4 Oct 2004||13 Jul 2006||Color Kinetics, Inc.||Methods and apparatus for generating and modulating white light illumination conditions|
|US20060261470 *||5 Apr 2006||23 Nov 2006||Tir Systems Ltd.||Electronic device package with an integrated evaporator|
|US20060285325 *||28 Aug 2006||21 Dec 2006||Color Kinetics Incorporated||Conventionally-shaped light bulbs employing white leds|
|US20070013322 *||1 Sep 2004||18 Jan 2007||Koninklijke Philips Electronics N.V.||Led temperature-dependent power supply system and method|
|US20090189530 *||23 Apr 2007||30 Jul 2009||Tir Technology Lp||Method and apparatus for light intensity control|
|US20110025213 *||3 Feb 2011||Po-Ying Liao||Wisdom tech led current balance assembly|
|US20120235575 *||11 May 2012||20 Sep 2012||Roberts John K||Solid State Lighting Panels with Variable Voltage Boost Current Sources|
|US20130009560 *||14 Sep 2012||10 Jan 2013||Mitsubishi Chemical Corporation||Illumination light control apparatus and led illumination system|
|US20130154518 *||14 Dec 2012||20 Jun 2013||Jeffrey Paul Davies||Systems and methods for data communication from an led device to the driver system|
|US20130241428 *||26 Mar 2013||19 Sep 2013||Mitsubishi Chemical Corporation||Led illumination apparatus and led illumination system|
|US20130293113 *||6 May 2013||7 Nov 2013||Starfield Controls Inc.||Self Calibrating, Adaptive Setpoint Daylighting|
|EP1555860A1 *||30 Nov 2004||20 Jul 2005||TridonicAtco GmbH & Co. KG||DC-fed driving modules for light sources|
|WO2011039678A1||21 Sep 2010||7 Apr 2011||Koninklijke Philips Electronics N.V.||Dimming of led driver|
|WO2014172103A1 *||2 Apr 2014||23 Oct 2014||Cirrus Logic, Inc.||Self-oscillating resonant converter-based light emitting diode (led) driver|
|U.S. Classification||235/454, 235/462.25|
|International Classification||H05B33/08, H05B37/02|
|Cooperative Classification||H05B33/0815, H05B33/0827, H05B33/0866|
|European Classification||H05B33/08D3K4, H05B33/08D1C4, H05B33/08D1L2P|
|16 Mar 2001||AS||Assignment|
|29 Jun 2006||FPAY||Fee payment|
Year of fee payment: 4
|20 Jul 2010||FPAY||Fee payment|
Year of fee payment: 8
|24 Jul 2014||FPAY||Fee payment|
Year of fee payment: 12